[37.07] The Emission of Gas from the Surface of Comets

J. Benkhoff (DLR - Berlin, Germany)

Sublimation of minor gases from ices inside of a porous
comet nucleus strongly depends on the chemical and physical
parameters of the nucleus. Our main objective is to find a
clue to determine conditions in the solar nebula from
chemical composition and structure of the nucleus Our model
describing the gas and dust flux out of a porous nucleus has
been used to study the influence of these parameters on the
gas flux. We solve the conservation equations for H2O,
CO, CH3OH, HCN, H2S, C3H4,
C2H2, C2H6 and other minor abundant
components under appropriate boundary conditions. Further,
we assume different orientations of the spin axis and take
seasons into account. We make some extreme assumptions on
the composition and the structure of the nucleus to
systematically analyze the resulting dust and gas fluxes.
Our results obtained for model comets in the orbit of
Hale-Bopp and Wirtanen are in very good agreement with
measured data.